In such a known apparatus, a centrifugal adjuster is provided which acts upon the fuel quantity adjusting device counter to the force of the governor spring, which is prestressed by the adjusting lever. Beyond a predetermined deflection of the adjusting sleeve of the centrifugal governor, communication is furnished between the suction chamber of the injection pump and an outflow line, in which a throttle is arranged to provide a control pressure which serves to actuate an exhaust recirculation dispensing device. The extent of communication between the suction chamber and the outflow line is continuously varied in accordance with the displacement of the fuel quantity adjusting device, so that for adjusting the exhaust recirculation dispensing device a control pressure is established which varies with the position of the fuel quantity adjusting device. The arrangement is such that a full load the recirculation of exhaust gas is precluded and at partial load fuel is supplied.
The apparatus of the prior and background art has the disadvantage, however, that the rpm dependency of the fuel quantity supply when the position of the fuel quantity adjusting device remains the same is not taken into consideration. This characteristic of the fuel injection pump means that while at low rpm the position of the fuel quantity adjusting device can still be utilized as a control variable for the quantity of recirculated exhaust gas, fuel quantities are injected, with the fuel quantity adjusting device remaining in a constant position, even in the middle rpm range at which a recirculation of exhaust gas should no longer be effected, for reasons having to do with soot emission and engine output. It is accordingly not assured that a sufficiently large quantity of exhaust gas can be recirculated at all operational rpm levels of the engine, except in the starting and warmup range, while fully exploiting the permissible limits of exhaust gas recirculation.